Ability of patients to accurately recall the severity of acute painful events.

OBJECTIVE: Pain studies require prospective patient enrollment to ensure accurate pain assessment. The authors correlated pain assessments of an acute painful episode over a one-week period and determined the accuracy of patient pain severity recall over time.
METHODS: This was a prospective, descriptive, longitudinal study. Participants were a convenience sample of 50 emergency department patients with acute pain resulting from injuries or painful invasive procedures. A trained research assistant administered a structured pain survey containing demographic and historical features to all patients. Patients sequentially assessed their pain severity using a vertical 100-mm visual analog scale marked "most pain" at the top, a verbal numeric rating scale ranging from 0 to 100 from none to worst (NRS100), and a verbal numeric rating scale ranging from 0 to 10 from none to worst (NRS10). Patients were contacted by phone and asked to reassess their initial pain severity one and seven days later using the two verbal numeric rating scales. Analysis of pain assessments using the various scales at the three time intervals was performed with Pearson's and Spearman's coefficients and repeated-measures analysis of variance (ANOVA).
RESULTS: There were 50 patients with a mean age of 41 years. Correlation between initial pain assessments on the three scales ranged from 0.83 to 0.92. Correlations between the initial and 24-hour assessments were NRS100-0.98 and NRS10-0.98. Correlations between the initial and one-week assessments were NRS100-0.96 and NRS10-0.97. Repeated-measures ANOVA showed no significant change in pain assessments over time for both verbal numeric scales.
CONCLUSIONS: Pain severity assessments of acute painful events one and seven days later were similar and highly correlated with initial assessments using both verbal numeric scales. Patients accurately recall the severity of an acute painful episode for at least one week after its occurrence, which may allow retrospective pain assessments.